Apparatus and method for controlling cold air circulation in refrigerator

ABSTRACT

The present invention relates to an apparatus and method for controlling cold air circulation in a refrigerator. The present invention re-circulates cold air, which has been discharged into a refrigerating chamber ( 35 ), so that the interior of the refrigerating chamber ( 35 ) can be maintained at a substantially uniform temperature and relatively low temperature cold air is prevented from being delivered to an evaporator ( 39 ). Particularly, the present invention further facilitates the cold air circulation at a lower portion of the refrigerating chamber ( 35 ) so that the temperature of the entire refrigerating chamber ( 35 ) can be kept to be uniform and the temperature of a vegetable storage chamber ( 36 ) can be set at a desired temperature. To this end, an embodiment of the present invention includes a circulation duct ( 50 ) configured to suck the cold air around the vegetable storage chamber ( 36 ) and to discharge it to a relatively upper portion of the refrigerating chamber ( 35 ). An inlet ( 51 ) of the circulation duct ( 50 ) is installed in vicinity of a reward lower portion of the vegetable storage chamber ( 36 ), and an outlet of the circulation duct ( 50 ) is open to above a shelf ( 35 ′) corresponding to a top end of the vegetable storage chamber ( 36 ). Further, a circulation fan ( 54 ) is installed at the outlet ( 52 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a refrigerator, and more particularly,to an apparatus for controlling cold air circulation in a refrigerator,which allows the internal temperature throughout a refrigerating chamberof the refrigerator to be uniformly distributed.

2. Description of the Prior Art

FIG. 6 shows a sectional view of a refrigerator which employs aconventional apparatus for controlling cold air circulation therein. Asshown in this figure, a freezing chamber 3 and a refrigerating chamber5, which are-storage spaces formed in the interior of a main body 1 ofthe refrigerator, are separated from each other by a barrier 4. Aplurality of shelves 5′ are installed at different levels in therefrigerating chamber 5 so that stored goods can be put on the shelves.A vegetable storage chamber 6 for separately storing fruits orvegetables therein is formed at a lowermost portion of the refrigeratingchamber 5. In general, the vegetable storage chamber 6 is constructed inthe form of a drawer.

The freezing chamber 3 and the refrigerating chamber 5 are opened andclosed by doors 7, 7′, respectively, so as to communicate with theexterior thereof Inner surfaces of the doors 7, 7′ are provided withdoor baskets 8 for accommodating stored goods.

Meanwhile, an evaporator 9, which is one of constituent components of aheat exchange cycle for generating cold air to circulate in therefrigerator, is installed in the rear of the freezing chamber 3. Aspace in which the evaporator 9 is installed is shielded by a shroud 10.A grill fan 12 is mounted between the shroud 10 and the freezing chamber3. Further, in order to circulate the cold air generated by theevaporator 9, a blower fan 14 is installed above the evaporator 9. Theblower fan 14 causes the cold air to flow into a space between theshroud 10 and the grill fan 12. The grill fan 12 is also provided with adischarge port (not shown) through which the cold air is discharged tothe freezing chamber 3.

Moreover, the cold air which has flowed downward through between theshroud 10 and the grill fan 12 is supplied to the refrigerating chamber5 through the barrier 4. To this end, a refrigerating chamber duct 16 isinstalled in the rear of the refrigerating chamber 5 such that itextends lengthily from an upper end of the refrigerating chamber to alower end thereof The refrigerating chamber duct 16 is formed with coldair discharge ports 17 through which the cold air is discharged tospaces partitioned by the shelves 5′.

Then, a freezing chamber return flow passage 18 is formed such that thefreezing chamber 3 communicates with the space with the evaporator 9installed therein through a top surface of the barrier 4 correspondingto a floor of the freezing chamber 3. The cold air which has circulatedin the freezing chamber 3 is returned to the evaporator 9 through thefreezing chamber return flow passage 18. Further, a refrigeratingchamber return flow passage 19 is formed such that the refrigeratingchamber 5 communicates with the space with the evaporator 9 installedtherein through a bottom surface: of the barrier 4 corresponding to aceiling of the refrigerating chamber 5.

However, there are the following problems in the conventional apparatusfor controlling the cold air circulation constructed as such.

In the prior art, as a refrigeration cycle is operated and the blowerfan 14 is also driven, the cold air which has circulated in therefrigerating chamber 5 is delivered through the refrigerating chamberreturn flow passage 19 to the evaporator 9 where heat exchange occurs,and then circulates in the refrigerator. Therefore, during the drivingof the refrigeration cycle, the temperature of the refrigerating chamber5 is relatively lowered since a great deal of cold air is delivered tothe refrigerating chamber 5. On the contrary, when the refrigerationcycle is stopped, the temperature of the refrigerating chamber 5 israpidly increased in a state where there is no cold air flow. In such away, if the cold air flow varies depending on the turning-on/off of therefrigeration cycle, the temperature deviation in the refrigeratingchamber 5 becomes larger. Consequently, freshness of the stored goods isdeteriorated.

Particularly, the cold air supplied to the refrigerating chamber 5through the refrigerating chamber duct 16 is relatively less influencedby the blower fan 14. Further, the cold air is relatively less deliveredto the door baskets 8 spaced far apart from the discharge port 17. Thus,the temperatures of the door baskets 8 are relatively higher than thosein the shelves 5′ located at the same levels as the baskets 8. Such aphenomenon becomes severest at a position corresponding to the positionof the vegetable storage chamber 6, which is a position of the lowermostone of the door baskets 8.

Moreover, an actual temperature of the vegetable storage chamber 6 isrelatively higher than an optimum temperature therein. This is becausethere is a relatively little amount of cold air which flows toward alower portion of the refrigerating chamber duct 16 and is then deliveredto the vegetable storage chamber 6. That is, according to the prior art,the cold air is not uniformly delivered to the entire refrigeratingchamber 5. Thus, it is likely that the temperature of a lower portion ofthe refrigerating chamber 5 becomes relatively higher, whereas thetemperature of an upper portion of the refrigerating chamber 5 becomesrelatively lower.

Thus, there are disadvantages as described below. Since the temperatureof the refrigerating chamber 5 is not uniformly set in such a way, thefreshness of foodstuffs stored in the lower portion of the refrigeratingchamber 5 is deteriorated. In addition since the cold air in theupper,portion of the refrigerating chamber 5 is returned to theevaporator 9 in a state where the cold air is at a relatively lowertemperature, heat loss occurs in the evaporator 9.

SUMMARY OF THE INVENTION

Therefore, the present invention is conceived to solve theaforementioned problems in the prior art. An object of the presentinvention is to minimize temperature deviation in a refrigeratingchamber of a refrigerator.

Another object of the present invention is to precisely maintain thetemperature of a vegetable storage chamber installed at a lower portionof the refrigerating chamber of the refrigerator.

A further object of the present invention is to minimize heat loss ofcold air which is returned from the refrigerating chamber to anevaporator.

According to an aspect of the present invention for achieving the aboveobjects, there is provided an apparatus for controlling cold aircirculation in a refrigerator, comprising a cold air supply means forsupplying cold air, which has been generated by a heat exchanger, to astorage space by using a blower fan; a cold air supply flow passage witha plurality of cold air discharge ports corresponding to respectiveportions of the storage space so that the cold air supplied from thecold air supply means is delivered to the storage space; a cold airreturn flow passage for returning the cold air, which has circulated inthe storage space, to the heat exchanger by means of suction force ofthe blower fan; a cold air circulation means for causing the cold air,which has been supplied from the cold air supply flow passage to thestorage space, to flow from a lower portion of the storage space to arelatively upper portion thereof; and a microcomputer for controllingthe cold air supply means and the cold air circulation means based oninformation on temperature of the storage space so as to circulate thecold air in the refrigerator.

The cold air circulation means preferably comprises a circulation fanfor sucking the cold air at the lower portion of the storage space, anda circulation duct of which an inlet is disposed at the lower portion ofthe storage space and an outlet is disposed at the relatively upperportion of the storage space so as to deliver the cold air sucked by thecirculation fan into the storage space again.

The circulation fan may be installed at the outlet or inlet of thecirculation duct.

The cold air circulation means may be installed within the cold airsupply flow passage, or at a side wall of the storage space which isseparate from the cold air supply flow passage.

The outlet of the circulation duct is preferably installed at the coldair discharge port of the cold air supply flow passage, and the inlet ofthe circulation duct is preferably positioned at a relatively lowerportion of the storage space.

The inlet of the circulation duct is preferably configured tocommunicate with a lower portion of an auxiliary storage chamber whichis separately formed at the lower portion of the storage space.

According to another aspect of the present invention, there is provideda method for controlling cold air circulation in a refrigeratorincluding a blower fan for circulating cold air, which has beengenerated by a heat exchanger, in a storage space and a circulation fanfor circulating the cold air from a relatively lower portion of thestorage space to a relatively upper portion thereof, comprising thesteps of determining, by a microcomputer, driving of the blower fan andthe circulation fan through comparison of a sensed temperature of thestorage space with a predetermined temperature; driving the blower fanbased-on the determination of the microcomputer and delivering the coldair, which has been generated by the heat exchanger, into the storagespace; and stopping the blower fan based on the determination of themicrocomputer and circulating the cold air, which has been deliveredinto the storage space, from the lower portion to the upper portion ofthe storage space by using the circulation fan.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the inventionwill become more apparent from reading the following description ofpreferred embodiment taken in connection with the accompanying drawingsin which:

FIG. 1 is a sectional view showing the constitution of a refrigeratorwhich employs a preferred embodiment of an apparatus for controllingcold air circulation in the refrigerator according to the presentinvention;

FIG. 2 is a front perspective view showing the constitution of a,refrigerating chamber according to the embodiment shown in FIG. 1;

FIG. 3 is a sectional view showing the constitution of a refrigeratorwhich employs another preferred embodiment of the present invention;

FIG. 4 is a partial front view showing the interior of the refrigeratingchamber, when viewed in a direction indicated by an arrow A in FIG. 3;

FIG. 5 is a graph showing the temperature of the refrigerating chamberdepending on the temperature of a compressor in the apparatus forcontrolling the cold air circulation according to the present invention;and

FIG. 6 is a sectional view showing a conventional structure for a coldair circulation flow in a refrigerator.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, preferred embodiments of an apparatus and method forcontrolling cold air circulation in a refrigerator according to thepresent invention will be described in detail with reference to theaccompanying drawings.

First, referring to FIGS. 1 and 2, one embodiment of the presentinvention will be described. As shown in these figures, the interior ofa main body 30 of a refrigerator, which is comprised of walls havinginsulation layers, is provided with a freezing chamber 33 and arefrigerating chamber 35 as storage spaces. The freezing chamber 33 andthe refrigerating chamber 35 are separated by a barrier 34 so that thefreezing chamber 33 and the refrigerating chamber 35 are disposed atupper and lower portions of the main body, respectively.

A plurality of shelves 35′ are installed in the refrigerating chamber 35so that stored goods can be put thereon. A vegetable storage chamber 36as an auxiliary storage space, which is separately formed by means ofpartitions so as to store fruits or vegetables, is installed at a lowerportion within the refrigerating chamber 35.

The freezing chamber 33 and the refrigerating chamber 35 selectivelycommunicate with the outside environment of the refrigerator by doors37, 37′, respectively. Inner surfaces of the doors 37, 37′ are providedwith a plurality of door baskets 38 for accommodating stored goods.

Meanwhile, an evaporator 39 as a heat exchanger, which constitutes arefrigeration cycle, is installed in the rear of the freezing chamber 33in order to generate cold air to circulate in the refrigerator. A spacebetween the evaporator 39 and the freezing chamber 33 is partitioned bya shroud 40 and a grill fan 42. A space between the shroud 40 and thegrill fan 42 serves to distribute the cold air to the freezing chamber33 and the refrigerating chamber 35. Here, the grill fan 42 is formedwith a plurality of discharge ports (not shown) through which the coldair is supplied to the freezing chamber 33. Further, a blower fan 44which provides driving force for causing the cold air to flow in therefrigerator is installed above the evaporator 39.

In order to supply the cold air into the refrigerating chamber 35, arefrigerating chamber duct 46 is installed in the rear of therefrigerating chamber 35. The refrigerating chamber duct 46 extendslengthily from an upper end of the refrigerating chamber to a lower endthereof, and is formed with cold air discharge ports 47 to correspond tothe respective shelves 35′. The cold air is delivered as far as thevegetable storage chamber 36 through the refrigerating chamber duct 46.

In order to return the cold air, which has circulated in the freezingchamber 33, to the evaporator 39, a freezing chamber return flow passage48 is formed through the interior of the barrier 34. Furthermore, inorder to return the cold air, which has circulated in the refrigeratingchamber 35, to the evaporator 39, a refrigerating chamber return flowpassage 49 is formed through the interior of the barrier 34. An inlet ofthe refrigerating chamber return flow passage 49 is formed on a bottomsurface of the barrier 34 which becomes a ceiling of the refrigeratingchamber 35.

Meanwhile, a circulation duct 50 is provided for further facilitatingthe cold air circulation in the lower portion of the refrigeratingchamber 35. Although the circulation duct 50 is installed in therefrigerating chamber duct 46 in this embodiment, it is not necessarilylimited thereto. The circulation duct 50 may be installed at a location,such as both side walls of the refrigerating chamber 35, separate fromthe refrigerating chamber duct 46.

An inlet 51 of the circulation duct 50 is disposed at a rearward lowerend of the vegetable storage chamber 36 to communicate with a lowerportion of the vegetable storage chamber 36. An outlet 52 of thecirculation duct 50 is disposed to be open to above a shelf 35′ which isplaced at a top end of the vegetable storage chamber 36. At this time,the outlet 52 is installed to penetrate through a portion of a frontsurface of the refrigerating chamber duct 46. The outlet 52 is alsoformed to communicate with the refrigerating chamber 35 via the cold airdischarge port 47.

Further, the outlet 52 of the circulation duct 50 is provided with acirculation fan 54 for circulating the cold air through the circulationduct 50. The circulation fan 54 causes the cold air, which has beensucked through the inlet 51, to be discharged into the refrigeratingchamber 35 through the outlet 52.

In the meantime, it is preferred that temperature sensors (not shown) bemounted so as to sense the temperatures within the refrigerating chamber35, the vegetable storage chamber 36 and the like. Information on thetemperature sensed by the temperature sensors are transmitted to amicrocomputer (not shown) and then used for determination of the drivingof the refrigeration cycle (i.e., driving of the blower fan 44) and thedriving of the circulation fan 54. The microcomputer determines thedriving of the blower fan 44 and the circulation fan 54 based onpredetermined data and the information on the temperature sensed by thetemperature sensors.

Hereinafter, the operation of the present embodiment having theaforementioned constitution will be described.

First of all, the cold air circulation performed in the refrigeratorwill be explained. When the refrigeration cycle is operated, acompressor (not shown) is driven and a refrigerant moves along therefrigeration cycle. Then, a relatively low temperature refrigerant issupplied to the evaporator 39 to generate the cold air.

The cold air generated by the evaporator 39 circulates in therefrigerator by means of the blower fan 44. That is, the cold air isdelivered to the space between the shroud 40 and the grill fan 42 by thedriving of the blower fan 44, and then, a portion of the cold air isdelivered to the freezing chamber 33 through the discharge ports of thegrill fan 42. The remainder of the cold air flows downward in the spacebetween the shroud 40 and the grill fan 42, passes through the barrier34 and is supplied to the refrigerating chamber duct 46.

The cold air delivered to the refrigerating chamber duct 46 flowsdownward along the refrigerating chamber duct 46 and is simultaneouslydischarged through the respective discharge ports 47 to above therespective shelves 35′ in the refrigerating chamber 35. The dischargedcold air cools the stored goods within the refrigerating chamber 35.

Then, the cold air which has been delivered to the freezing chamber 33and the refrigerating chamber 35 is returned to the evaporator 39through the freezing chamber return flow passage 48 and therefrigerating chamber return flow passage 49, respectively. Heatexchange occurs between the cold air and the refrigerant in theevaporator, and the cold air then repeatedly circulates in therefrigerator.

Meanwhile, the circulation fan 54 sucks the cold air on a side of thelower portion of the refrigerating chamber 35 and discharges it upward.It is preferred that the circulation fan 54 be driven when the blowerfan 44 is not operated. This is to prevent the vegetable storage chamber36 from being cooled too excessively due to continuous supply of thecold air, which is supplied from the evaporator 39 by the operation ofthe blower fan 44, to around the vegetable storage chamber 36.

Once the temperature of the refrigerating chamber 35 reaches apredetermined temperature, the operation of the heat exchange cycle isstopped and the operation of the blower fan 44 is also stopped. It ispreferable to operate the circulation fan 54 in this condition.

Namely, when the circulation fan 54 is operated, the cold air at therearward lower end of the vegetable storage chamber 36 is sucked throughthe inlet 51 of the circulation duct 50. Then, the sucked cold air isdischarged to above the shelf 35′ placed at the top end of the vegetablestorage chamber 36 through the outlet 52 of the circulation duct 50.With such circulation, a space between a leading end of the vegetablestorage chamber 36 and the door 37′ is supplied with the cold air fromthe upper portion of the refrigerating chamber 35. Here, the cold airdelivered from the upper portion of the refrigerating chamber 35 passesthrough around the vegetable storage chamber 36 and is sucked into theinlet 51 of the circulation duct 50. This cold air circulation isindicated by arrows in FIGS. 1 and 2.

In such a way, the relatively low temperature cold air can be deliveredparticularly to around the vegetable storage chamber 36 as well as thedoor baskets 38′ of the door 37′. Further, the relatively lowtemperature cold air can also be delivered to a lowermost door basket38′ of the door 37′ which otherwise might have a highest temperature.Thus, the lowermost basket 38′ can be set at a desired temperature.

Such an operation of the circulation fan 54 can be controlled based onsensed signals detected by a temperature sensor additionally installedin the vegetable storage chamber 36. That is, when the temperature ofthe vegetable storage chamber 36 reaches a predetermined temperature,the circulation fan 54 is stopped in response to the sensed signalsdetected by the temperature sensor.

Next, another embodiment of the present invention is shown in FIGS, 3and 4. When describing the constitution of this embodiment, onlyelements different from those of the previous embodiment shown in FIG. 1will be described and like or similar elements are denoted by the samereference numerals as FIG. 1.

In order to further facilitate the cold air circulation in therefrigerating chamber 35, the present embodiment employs a circulationduct 150. The circulation duct 150 of the present embodiment is not alsonecessarily installed in the refrigerating chamber duct 46 and may beinstalled at a location, such as both the side walls of therefrigerating chamber 35, separate from the refrigerating chamber duct46.

A circulation fan 152 is installed at an inlet 151 which is disposed ata lower end of the circulation duct 150. The inlet 151 of thecirculation duct 150 is fitted into and installed at a circulation inlet47′ of the refrigerating chamber duct 46. Thus, the circulation fan 152is positioned inside the circulation inlet 47′ so that the cold airwithin the refrigerating chamber 35 can be sucked thereinto.

The circulation duct 150 is installed in the refrigerating chamber duct46 to extend lengthily in an up and down direction and is provided withrespective outlets 154 at locations corresponding to the discharge ports47 formed in the refrigerating chamber duct 46. The outlets 154 areformed at the locations corresponding to the discharge ports 47 so thatthe cold air flowing through the circulation duct 150 can be supplied tothe refrigerating chamber 35 through the discharge ports 47. At thistime it is preferable to make cross-sectional areas of the outlets 154smaller than those of the discharge ports 47. Further, although eachoutlet 154 can be installed to be fitted into a portion of eachdischarge port 47, it is not necessarily limited thereto. The outlets154 may be arranged to be disposed in the vicinity of the dischargeports 47 in the same way as the illustrated embodiment.

Hereinafter, the operation of the present embodiment as constructed assuch will be briefly described. The present embodiment is the same asthe previous embodiment in that the cold air generated by the evaporator39 is delivered to the freezing chamber 33 and the refrigerating chamber35 by means of the blower fan 44, and in that the cold air delivered tothe freezing chamber 33 and the refrigerating chamber 35 is returnedthrough the respective freezing chamber return flow passage 48 andrefrigerating chamber return flow passage 49 to the evaporator 39 wherethe heat exchange occurs between the cold air and the refrigerant in theevaporator and then repeatedly circulates in the refrigerator.

Meanwhile, the circulation fan 152 sucks the cold air on a side of theinterior of the refrigerating chamber 35 and then discharges it to theother side. It is preferable to drive the circulation fan 152 when theblower fan 44 is not operated. Alternatively, the circulation fan 152may be driven together with the blower fan 44 so that the relatively lowtemperature cold air cannot be returned to the evaporator 39.

Once the temperature of the refrigerating chamber 35 reaches apredetermined temperature, the operation of the heat exchange cycle isstopped and the operation of the blower fan 44 is also stopped. It ispreferable to operate the circulation fan 152 in this condition.

That is, the temperatures in the vicinity of the lower portion and thevegetable storage chamber 36 of the refrigerating chamber 35 aregenerally higher than the predetermined temperature. This is because thelower portion and the vegetable storage chamber 36 of the refrigeratingchamber 35 are portions corresponding to a distal end of therefrigerating chamber duct 46.

Therefore, when the circulation fan 152 is operated, the cold air flowindicated by arrows in FIGS. 3 and 4 is generated within therefrigerating chamber 35. With such cold air flow, the entire interiorof the refrigerating chamber 35 can be kept at a uniform temperature.

In other words, when the circulation fan 152 is operated, the cold airat the lower portion of the refrigerating chamber 35 is sucked into thecirculation duct 150 through the circulation inlet 47′. Then, the suckedcold air is delivered to an upper portion of the circulation duct 150and discharged to a relatively upper portion of the refrigeratingchamber 35 through the respective outlets 154.

In particular, the cold air around the vegetable storage chamber 36 issucked into the circulation duct 150 by means of the driving of thecirculation fan 152 and the cold air at the upper portion of therefrigerating chamber 35 is simultaneously moved downward, so that thetemperature of the entire refrigerating chamber 35 can be kept to beuniform.

Referring to FIG. 5, there is well shown that the temperature of therefrigerating chamber 35 according to the present invention is kept tobe relatively uniform as time passes. The temperature of the compressoris plotted using a dotted line. The higher temperature of the compressormeans that the refrigeration cycle is running. The temperature of therefrigerating chamber depending on the temperature of the compressor isplotted using a one-dotted chain line in case of the prior art and usinga solid line in case of the present embodiment. As can be seen from thisfigure, in case of the present embodiment, the temperature deviationwith the elapse of time is relatively small and thus the refrigeratingchamber is kept at a substantially uniform temperature.

With the apparatus and method for controlling the cold air circulationin the refrigerator according to the present invention which have beendescribed in detail above, the temperature of the entire refrigeratingchamber can be kept to be uniform, and particularly, the vegetablestorage chamber disposed at the lowermost portion of the refrigeratingchamber and the lowermost door basket of the door can be maintained at adesired temperature.

Furthermore, according to the present invention, since the temperatureof the entire refrigerating chamber can be kept to be uniform, therelatively low temperature cold air is prevented from being delivered toand heat-exchanged with the evaporator. Thus, the efficiency of therefrigerator can be improved.

Although the present invention has been described herein with respect tothe preferred embodiments employed in an upright type refrigerator, itwill be understood by those skilled in the art that the presentinvention can be employed in a parallel type refrigerator within thescope of the invention defined by the appended claims.

1. An apparatus for controlling cold air circulation in a refrigerator,comprising: a cold air supply means for supplying cold air, which hasbeen generated by a heat exchanger, to a storage space by using a blowerfan, the storage space having an upper portion, a middle portion, and alower portion; a cold air supply flow passage with a plurality of coldair discharge ports corresponding to respective portions of the storagespace so that the cold air supplied from the cold air supply means isdelivered to the storage space; a cold air return flow passage forreturning the cold air, which has circulated in the storage space, tothe heat exchanger by means of suction force of the blower fan; a coldair circulation means comprising a circulation fan positioned at thelower portion of the storage space for causing the cold air, which hasbeen supplied from the cold air supply flow passage to the storagespace, to flow from the lower portion of the storage space only towardthe lower or middle portion thereof; and a microcomputer for controllingthe cold air supply means and the cold air circulation means based oninformation on temperature of the storage space so as to circulate thecold air in the refrigerator.
 2. The apparatus as claimed in claim 1,wherein the cold air circulation means further comprises a circulationduct of which an inlet is disposed at the lower portion of the storagespace and an outlet is disposed at the lower or middle portion of thestorage space so as to deliver the cold air sucked by the circulationfan into the storage space again.
 3. The apparatus as claimed in claim2, wherein the circulation fan is installed at the outlet of thecirculation duct.
 4. The apparatus as claimed in claim 2, wherein thecirculation fan is installed at the inlet of the circulation duct. 5.The apparatus as claimed in claim 2, wherein the cold air circulationmeans is installed within the cold air supply flow passage.
 6. Theapparatus as claimed in claim 2, wherein the cold air circulation meansis installed at a side wall of the storage space which is separate fromthe cold air supply flow passage.
 7. The apparatus as claimed in claim2, wherein the outlet of the circulation duct is formed at the cold airdischarge port of the cold air supply flow passage.
 8. The apparatus asclaimed in claim 7, wherein the inlet of the circulation duct ispositioned at the lower portion of the storage space.
 9. The apparatusas claimed in claim 8, wherein the inlet of the circulation duct isconfigured to communicate with a lower portion of an auxiliary storagechamber which is separately formed at the lower portion of the storagespace.
 10. A refrigerator comprising the apparatus of claim
 1. 11. Anapparatus for controlling cold air circulation in a refrigerator,comprising: a cold air supply device configured to supply cold air to astorage compartment, the storage compartment having an upper portion, amiddle portion, and a lower portion; a cold air supply flow passagehaving one or more cold air discharge ports configured to deliver thecold air supplied from the cold air supply device to the respectiveportions of the storage compartment; a cold air return flow passageconfigured to return the cold air, which has circulated in the storagecompartment, to the cold air supply device; and a cold air circulationdevice comprising a circulation fan positioned in the lower portion ofthe storage compartment and configured to force cold air, which has beensupplied from the cold air supply device, from the lower portion of thestorage compartment only toward the lower or middle portion of thestorage compartment.
 12. The apparatus as claimed in claim 11, whereinthe cold air circulation device is positioned adjacent an auxiliarystorage compartment within the storage compartment and configured tosupply the cold air, which has been supplied from the cold air supplyflow passage, to the auxiliary storage compartment.
 13. The apparatus asclaimed in claim 12, wherein the auxiliary storage compartment isseparately formed at the lower portion of the storage compartment. 14.The apparatus as claimed in claim 11, further comprising: amicrocomputer configured to control the cold air supply device and thecold air circulation device based on a temperature of the storagecompartment.
 15. The apparatus as claimed in claim 11, furthercomprising a blower fan configured to cause cold air to flow from thecold air supply device through the cold air supply flow passage into thestorage compartment.
 16. The apparatus as claimed in claim 11, whereinthe cold air circulation device further comprises a circulation duct, aninlet of which is disposed adjacent to an auxiliary storage compartmentpositioned within the storage compartment.
 17. The apparatus as claimedin claim 16, wherein the circulation fan is installed at the outlet ofthe circulation duct.
 18. The apparatus as claimed in claim 16, whereinthe circulation fan is installed at the inlet of the circulation duct.19. The apparatus as claimed in claim 16, wherein the outlet of thecirculation duct is formed adjacent one of the one or more cold airdischarge ports.
 20. The apparatus as claimed in claim 19, wherein theinlet of the circulation duct is positioned in the lower portion of thestorage compartment.
 21. The apparatus as claimed in claim 11, whereinthe cold air circulation device is installed within the cold air supplyflow passage.
 22. The apparatus as claimed in claim 11, wherein the coldair circulation device is installed at a side wall of the storagecompartment which is separate from the cold air supply flow passage. 23.A refrigerator comprising the apparatus of claim 11.